This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. During early puberty, LH frequency normally increases during sleep. In contrast, preliminary data suggest that obese girls (who are hyperandrogenemic in general) demonstrate low LH frequency during the day and night during early puberty;but at mid puberty rapidly transition to a high LH frequency during the day and night. Thus, we hypothesize that in early pubertal girls with hyperandrogenemia, overnight increases of LH (GnRH) frequency are less prominent than those observed in early pubertal girls without hyperandrogenemia. We propose to assess this further using a frequent sampling protocol for assessment of LH pulse frequency (with sampling occurring while awake and while asleep) in early pubertal girls with and without hyperandrogenemia. The data will be analyzed by way of hierarchical mixed-effects ANCOVA models.